ABB RELION REX640 Technical Manual page 1203

1MRS759142 F
t
TRIGG_T
TRIGG_REC
t
0
Figure 685: Fault distance estimate triggering moment definitions
Fault loops "AB Fault", "BC Fault" or "CA Fault"
Fault loops "AB Fault", "BC Fault" or "CA Fault" are used for phase-to-phase short
circuit faults as well as in the case of a two-phase-to-earth fault if the individual
earth faults are located at the same feeder.
fault loop model. The following impedances are measured and stored in the
recorded data of SCEFRFLO.
Flt point resistance
REX640
Technical Manual
0.025
Fault indication
0.02
0
Fault start transition
settle-down
0.015
Settling down delay
0.01
0.005
0
-0.005
-0.01
1300
Fault indication
Fault start transition
settle-down
0.03
Settling down delay
0.02
0.01
0
-0.01
-0.02
1200 1300
R
fault
=
2
G0 (blue) and G0 difference (red)
t
1
t
2
Zero conductance gradient
rising edge
1400 1500 1600
Time delay
G0 (blue) and G0 difference (red)
t
1
t
2
Zero conductance gradient
rising edge
1400 1500
Figure 686
Protection related functions
1700 1800
1600 1700
shows the phase-to-phase
(Equation 299)
1800
1203